Look on your map and look for map about 1/2 way down toward moddle of western part of Feerrott. There is a stone bridge called Gogoth bridge. Just east of Gogoth bridge are several of the critters in question. You can stand on the bridge and see them and shoot them they are that close to it.
There are about four that spawn individually and there is a pack of four. If your soloing be careful not to target the pack unless your feeling lucky.